Froth flotation process



Patented A 15, 1941 FROTH'FLOTATION PROCESS William T. Bishop,Wilmington, 11.1., assignor to Hercules Powder Company, Wilmington,Del., a corporation of Delaware N Drawing. Application July 25, 1939,Serial No. 286,321

8 Claims. (Cl. 209-166) This invention relates to a process forconcentrating minerals and more particularly to a truth flotationprocess for concentrating non-metallic minerals.

Heretofore, fatty acids, soaps, or analogous surface active reagentshave been utilized as froth flotation agents for non-metallic minerals.These reagents generally were quite unsatisfactory because the siliceousmineral could not be readily floated and large quantities of flotationreagent were required. The resulting concentrates had a low yield and,due to ineffective separation of undesirable materials, were of inferiorquality. Also, the reagents were unsatisfactory as the desiredselectivity" of materials to be separated could not be obtained and thepH and reagent concentrations had to be maintained within relativelynarrow limits.

Recently attempts have been made to float nonsulfide minerals by usingcomplex nitrogen derivatives such as quaternary ammonia compounds.However, the high cost of these compounds mitigates against their use asflotation agents, particularly for use in floating low price minerals.

An object of this invention is to provide an improv-ed froth flotationprocess for concentrating non-metallic minerals.

Another object is toprovide a froth flotation product for concentratingnon-metallic minerals from ores containingnon-metallic and/or sulfideminerals.

Another object is to provide a froth flotation process which iseconomical and eflicient in operv ation.

Another object is to provide a froth flotation process for producinghigh concentrations of nonmetallic minerals which formerly could not beseparated or could be concentrated only with great difflculty.

Another object is to provide a froth flotation process whereinrelatively small amounts of flotation reagents are employed and the pHof the circuit may vary over a relatively wide range.

A further object is to provide an improved flotation process wherein acomparatively inexpensive, readily available froth flotation reagent isemployed.

Other and further objects will be obvious upon an understanding of theillustrative embodiment about to be described, or will be indicated inthe appended claims, and various advantages not referred to herein willoccur to one skilled in the art upon employment of the invention inpractice. These objects are accomplished by frothing an aqueoussuspension of non-metallic minerals in 'the presence of'a reactionproduct of a chlorin-.

ated hydrocarbon of the paraffin series and am:

monia. These reaction products contain a positively charged surfaceactive ion and are adapted The froth flotation process preferablyis'c'arried out with to concentrate non-sulfide minerals.

persing agent. a

In accordance with the invention, I have found that a frother known tothe trade as Du Ponts B23, which is a mixture of aliphatic alcohols anda dispersing agent known to the trade as American Cyanamids No. 610,which is a lignin sulfonate, can be advantageously utilized inconjunction with the chlorinated hydrocarbon-ammonia reaction products.If desired pine oil may be used as a frother and Goulac, a product ofWaste sulfite liquors may be used as a dispersing agent.

The chlorinated hydrocarbon-ammonia reaction products which I employ,may be prepared from hydrocarbons containing between about eight andabout thirty carbon atoms but preferably are prepared from paraifin waxor similar hydrocarbon compounds of the paraflin series containingbetween twenty-two and twenty-eight carbon atoms and designated by theformulas, C22H4c, C23H4a, C24H50, C25H52, C2sH54, C27H58, and CasHsa.These products are prepared by chlorlnating paraffin wax or othersuitable hydrocarbons in any well-known manner'to contain from 10 to 70%chlorine and preferably from 20 to chlorine; and then reacting thechlorinated product with ammonia. Such products contain a positivelycharged surface active ion and are very effective in concentrating,floating, and collecting non-metallic minerals, particularly suchminerals which are free from sulfides.

I have found that the following products can be made economically in asimple manner:

the aid of a frothing agent or'frother, and a dis- Products CompositionA A 52% chlorinated paraffin-ammonia reaction product containing 7.1%nitrogen and 14.0% chlorine.

B A 30% chlprmated paraflin-ammonia reaction product containing 6.0%nitrogen and 12.3% chlorine.

BHC1 e B Wlthamines converted to hydrochlorides.

B A grgiolgc similar to B which is heated for three hours C A 21%chlorinated paraflln-ammonia reaction product containing 4.5% nitrogenand 8.0% chlorine.

C-HCL Like 0 with amines converted to hydrochloridcs.

To determine .the effectiveness of the foregoing described products, 200g. of +200 mesh deslimed quartz and water wereplaced in a flotation-celland'were agitated. The frother and product under test were added in theamounts shown in the following table and air was passed therethrough andthe pH of the circuit was maintained as designated.

' Flotation of quartz with. chlorinated parafilnammonia reactionproducts These tests indicated that satisfactory quartz collectors canbe produced by reacting ammonia with chlorinated paraflins which containfrom 21 to 52% chlorine. contain from 4.5 to 7.1% nitrogen and from 8.0to 14.0% chlorine and can be used efliciently in the presence of afrother at concentrations between .07 and .12 lb./ton while maintaininga. pH varying over a wide range, for example, between 62 and 9.5, andmaintaining reagent concentrations between .10 to .12 lb./ton. Theproducts also are eflicient when used without a frother at reagentconcentrations of about .10 to .12 lbs/ton and a pH between 6.2 and 8.0.The collectin'g properties of the product 131 were not changed byheating three hours at 200 C. thus indicating that the product is verystable.

In another test 200g. of 65 +200 mesh deslimed feldspar wasused insteadof quartz and The reaction products may.

theforegoing described procedure was followed using product B in anamount corresponding to .40 lb./ton of feldspar at a pH of 6 with .061b.'/ton of 3-23 frother. A 100% recovery was obtained. The foregoingtests illustrate the collecting properties of the products onnon-sulfide minerals namely, quartz and feldspar. As demonstrated by thefollowing examples, the products are suitable for separating silicatesfrom carbonates in siliceous limestone slurry where the problem is toreadjust the relative. proportions of the calcareous and siliceousmaterials. The slurry contains on an average 70% calcite (including asmall amount of dolomite), 15% mica, and quartz and feldspar equal toabout 15%. Removal of some of the last three mentioned constituents isnecessary to prepare a suitable cement mix.

To accomplish this, the slurry was first deslimed and the more granularpart of the material was froth flotated in the presence of a chlorinatedparaflln-ammonia reaction product.

The resulting concentrate was rich in silicates and left a tailingcontaining a high percentage of calcite corresponding to a goodrecovery. By

floating the silicates, which constitute a minor proportion of theslurry, the carbonates and silicates are more quickly separated andwithout using a. relatively large quantity of flotation agents. Thisgreatly increases plant capacity and decreases the cost of the flotationprocess.

' Example I First 1,000 cc. of cement rock slurry, prepared from a rockcontaining 68.19% CaCOa and 23.79% insoluble, was diluted to about 15liters with tap water. The slurry was well mixed and then 1% minuteswere allowed for settling. The'slimes were siphoned of! down to a volumeof about 4 liters. This operation was. carried out for two additionaltimes. The deslimed material was then transferred to a 1,000 gramflotation cell for the actual test. Thereafter 5 cc. of a 1%solution ofa 30% chlorinated paraffin-ammonia reaction productv in the form ofhydrochloride, product B-HC1, was added, and a concentrate was taken offfor about 3 minutes. Then a second concentrate was collected for thesame time by the addition of 2.5 cc. of product B-HCl solution at 0.095lb./ton. The following, metallurgical results were obtained:

About 900 cc. of cement rock slurry prepared from a rock containing 63.8to 64.0% CaCOa and 26.1 to 26.2% insoluble materials was diluted toabout 15 liters with tap water. To this was added 1 gram of a dispersingagent, No. 610 (American Cyanamid), and after being well mixed with theslurry, the slimes were removed as described in Example I. The test wasmade in a 1,000 gram flotation cell and, .06 lb./ton of 3-23 alcoholfrother was added and then 4 cc. of 1% solution of the hydrochloride ofa 30% chlorinated paraflin-ammonia reaction product, corresponding toreaction product BHC1 at .14 1b./ton. A concentrate was collected for 5,minutes. The metallurgical results of which were as follows:

. Recovery Percent Insoluble Weight 0800;

Insol- Caco' uble Percent Percent Percent 6. 0 94. 0

Concentrate 22.7 T8 429 77.3 37.5

Example III The method of desliming the cementrock slurry in thepresence of 1 gram of a dispersing agent was carried out in the samemanner as in Example II. B-23 alcohol frother equal to a .12

; lb./ton concentration was added and 2 cc. of 1% solution of a 30%chlorinated paraflin-ammonia reaction product, product B, was introducedand concentrate No. 1 was collected for '3 minutes.

Then 1 cc. more of the same solution (product B) was added andconcentrate No. 2 was taken oif for 3 minutes. The metallurgical resultswere as follows:

pared from a rock containing about 64 .3 cacoi Percent and about 24.2%insoluble were deslimed separately in the presence of 1 gram ofdispersing agent No. 610 by following the same procedure in each case asgiven under Example II. The total deslimed material from both portionswas transferred to the 1,000 gram Denver Sub A flotation cell and theseparation made. 0.06 lb./ton of 3-23 alcohol frother was added. Then 2cc. of 1% solution of chlorinated paraflinqammonia reaction product(0.04 lb./ton) was introduced which gave concentrate No. 1, collectedfor 3 minutes. Concentrate No. 2, collected for 2 minutes, was producedby an additional 1 cc. of the same reagent (0.02 lb./ton). Likewiseconcentrate No. 3, collected for 2 minutes, resulted from an additional1 cc. of the reagent at 0.02 lb./ton, (total for test 0.08 1b./ton).Metallurgical results were as follows:

About 1,000 cc. of cement rock slurry, prepared from a rock containing65.8% CaCOs and 23.9% insoluble, was deslir'ned in the same manner asgiven under Example 11, except Goulac, a product from waste sulfiteliquors, probably a lignin sulfonate, was used instead of the dispersionagent No. 610. This test was made on the deslimed material in a 1,000 g.flotation cell and a quantity of 3-23 alcohol irother equal to a .06 lb/ton concentration was added. Then 2 cc. of 1% solution of 30%chlorinated parafin-ammo- ,nia reaction product (product B) equalto 0.08lb./ton was added providing concentrate No. l, which was collected for 3minutes. A second concentrate, collected for 3 minutes, was pro duced bythe addition of 2 co. more of thesame solution of reagent (0.08lb./ton). The metallurgical results were as follows:

Recovery Weight 0860 cent a uble Insol uble Gram Percent Percent PercentPercent ConoentrateNo.l. 14 2.8 12.93 71.78 0. 8. Concentrate No.2, 8717.3 18.05 69. 87 4.8 50.6 Tail 401 79.9 77.97 12.26 94.7 41-0 Theproblem in connection with the above ex- I amples on cement rock, is thepreparation of high grade lime product. The above examples show thatchlorinated paraifln-ammonia reaction products collect the siliceousmaterial and leave behind a high grade calcite tailing containing from'18 to 85% CaCOa. The reagent is very efficient and as little as .10 to0.15 lb./ton of rock is required. The reagent has a high selectivity forthe silica as well. As illustrated by the fact that the amount ofcalcite in the tailing corv responds to 84 to 95% recovery.

Example VI Under proper controlled conditions it is possible to separateother non-metallic minerals aflin-ammonia reaction products. This isshown by the following tests. Here the material worked with is a kyanitetailing containing about 6% kyanite (AlzSiOs), the balance being quartz,black mica and garnet (dark purple). While limiting the amount of thereagent to 0.4 to 0.5 lb.7ton, it is possible to separate the mica andgarnet from the quartz and kyanite. The quartz does not float along withthe other two. Because of the differences in color of the mica andgarnet, the separation could be readily observed. The tailing waspractically white with a little rosecolored quartz mixed in. The kyanitecontents were determined, which is a check on the selectivity of theproduct.

Twohundred g. of 48-mesh kyanite tailings and distilled water wereplaced in the flotation cell and while agitated, pine oil to the extentof 0.07 lb./ton was added. Then 0.50 lb./ton of the 30% chlorinatedparaflln-ammonia reaction product was introduced. Air was then passedthrough and a concentrate was taken oil for 5 minutes. The dark coloredmica and garnet readily flocculated and floated.- The tailing was 21.5%of the total and analyzed 21.8% kyanite, which corresponds to 95.5%kyanite recovery.

Another test carried out in exactly the same manner with 0.04. lb./tonof the same product gave a tailing equal to 37.2% of the total andanalyzed 15.7% kyanite which corresponds to a- 96.8% recovery.

Numerous other sulfide or non-sulfide ores might be substituted in placeof the ores floated in the foregoing mentioned examples. .While thisinvention relates particularly to the flotation of negatively chargedminerals, it is to be understood that it is not limited thereto and mayirequently be used to float positively charged min... erals. It may beapplied to both sulfide and nonsulfide ores. When applied to the former,the flotation agents described herein may be used along with thecustomary flotation agents for sulfide ores such as collectors,frothers, conditioners, depressants, dispersing agents, etc. Whenapplied to non-sulfide ores which contain a positive charge, theflotation agents described herein may be mixed with soap, soap-likeproducts, sulionated products, etc., and other ilota-= tion agents. Theproportions of the individual components in such admixtures may varywithin wide limits.

From the foregoing description and. examples,

' it will be seen that the present invention provides from quartz andsilicate with chlorinated para simple, rapid, and inexpensive processfor collecting non-sulfide, non-metallic minerals. The yield attained bythe process is highly satisfactory and can be attained at a very lowcost. The

products employed as collectors are relatively inexpensive and arereadily available. Due to their low cost, they can be used for frothflotation of low price minerals which do not allow the use of the highprice materials used heretofore as collectors. Also relatively smallamounts of flotation reagents are used and the pH of the circuit mayvary over a wide range.

It will be understood that the details and examples hereinbefore setforth are illustrative only and that the invention as broadly describedand claimed is in no way limited thereby.

What I claim and desire to protect by Letters Patent is:

1. A process for the froth flotation of ne tively charged minerals whichcomprises fro ing an aqueous suspension of the minerals in the presenceor a reaction g'product of chlorinated paraflin-hydrocarbons havingbetween twentytwo and thirty carbon atoms and ammonia, said producthaving a positively charged surface active ion.

2. A process for the froth flotation of nonsulflde, non-metallic,negatively charged miner als which comprism frothing an aqueoussuspension of the minerals in the presence of a reaction "product ofchlorinated paraffin-hydrocarbons having between twenty-two andthirtycarbon atoms and ammonia, said product having a positively chargedsurface active ion.

3. A process for the froth flotation of nonnietallic minerals whichcomprises irothing an aqueous suspension of the minerals in the presenceof a reaction product of a chlorinated waxlike paraffin-hydrocarbon andammonia containing 4 to 8% nitrogen and 8 to 14% chlorine.

4. A process for the froth flotation of nonmetallic minerals whichcomprises frothing an aqueous suspension of minerals in the presence.

of a reaction product of a chlorinated wax-like paraffin-hydrocarbon,which contains from 21 to 52% chlorine, with ammonia.

5. A process for the froth flotation of nonmetallic minerals whichcomprises frothing an aqueous suspension of minerals in the presence ofa reaction product of wax-like paraffin-hydrocarbons and ammonia,maintaining the reaction productconcentration between .10 and .121b./ton and maintaining a pH between 6.2 and 9.5.

6. A process for the frothflotation or non-.

metallic minerals which comprises irothing an aqueous suspension ofminerals in the presence of a reaction product of wax-likeparaflin-hydro-. carbons and ammonia, maintaining the reaction productconcentration between .10 and .12 1b./ton and maintaining a pH between6.2 and 9.5, and adding a frother in amounts to provide concentrationsof between .07 and .12 1b./ton.

7. A process for the froth flotation 01 nonmetallic minerals whichcomprises frothing an WILLIAM T. BISHOP.

